Diff: FM25W256.cpp

Revision:

1:bb2b1e4bfb6e

Parent:

0:5a552209903c

--- a/FM25W256.cpp	Fri Mar 04 15:49:51 2016 +0000
+++ b/FM25W256.cpp	Sat Mar 05 14:05:39 2016 +0000
@@ -1,3 +1,28 @@
+/* Cypress FM25W256 F-RAM component library
+ *
+ * Copyright (c) 2016 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *  *
+ *  @author  Toyomasa Watarai
+ *  @version 1.0
+ *  @date    5-March-2016
+ *
+ *  http://www.cypress.com/products/nonvolatile-ram
+ *  http://www.cypress.com/documentation/datasheets/fm25w256-256-kbit-32-k-8-serial-spi-f-ram?source=search&keywords=FM25W256&cat=technical_documents
+ *
+ */
+
 #include "mbed.h"
 #include "FM25W256.h"
 
@@ -5,17 +30,18 @@
     : _spi(mosi, miso, clk), _cs(cs)
 {
     _spi.format(8, 0);
-    _spi.frequency(20000000);
+    _spi.frequency(FM25W256_CLK);
     _cs = 1;
+    wait_ms(1); // tPU = 1ms (min.)
 }
 
 FM25W256::FM25W256(SPI &spi, PinName cs)
     : _spi(spi), _cs(cs) 
 {
     _spi.format(8, 0);
-    _spi.frequency(20000000);
+    _spi.frequency(FM25W256_CLK);
     _cs = 1;
-
+    wait_ms(1); // tPU = 1ms (min.)
 }
 
 void FM25W256::write(uint16_t address, uint8_t data)
@@ -73,3 +99,38 @@
     }
     _cs = 1;
 }
+
+void FM25W256::wirte_status(uint8_t data)
+{
+    _cs = 0;
+    _spi.write(CMD_WREN);
+    _cs = 1;
+
+    _cs = 0;
+    _spi.write(CMD_WRSR);
+    _spi.write(data);
+    _cs = 1;
+}
+
+uint8_t FM25W256::read_status()
+{
+    uint8_t data;
+    _cs = 0;
+    _spi.write(CMD_RDSR);
+    data = _spi.write(0);
+    _cs = 1;
+    
+    return data;
+}
+
+void FM25W256::set_write_protect(E_WP bp)
+{
+    // Set WPEN, BP0 and BP1
+    wirte_status((1 << 7) | (bp << 2));
+}
+
+void FM25W256::clear_write_protect()
+{
+    wirte_status(0);
+}
+    
\ No newline at end of file